1. Field of the Invention
This invention relates generally to scanning objects and more particularly to generating a three-dimensional scan of an object using a handheld scanner.
2. Description of Related Art
Computer-aided design (CAD) systems may use a computer to modify a three-dimensional (3D) representation of an object. The CAD system may provide functionality for modifications that size, stretch, rotate, and otherwise make changes to the 3D representation. The modified representation may be used to produce instructions for controlling a computer-aided manufacturing (SAM) machine to fabricate a three-dimensional reproduction of the modified object.
For example, prostheses and orthoses are commonly produced from three-dimensional representations of a body part of a human or an animal. In some cases, generation of the prosthesis or orthosis is based on a 3D scan of the body part. A 3D scanner may be used to generate the 3D representation of the body part for use in the CAD system. One such scanner is the Spectra™ 3D handheld scanner produced by Vorum Research Corp. of Vancouver, BC, Canada. The Spectra 3D scanner projects a grid of light onto the body part of a patient or other object and captures images of the object while the operator moves the handheld scanner relative to the object. The images are transmitted to a scanner software program running on a computer, which processes the images to generate a set of 3D points representing surfaces of the object. For example, the object may be represented by a polygon mesh or triangular mesh having vertices that defined by 3D coordinates that lie on the surface of the object.
Handheld 3D scanners are convenient to use since additional equipment for mounting and moving the scanner is not required. However, operation by an inexperienced operator may result in images that are unsuitable for producing an accurate scan of the object. There remains a need for improved 3D scanning methods.